This invention relates to surgical fastener applying apparatus, and more particularly to apparatus for applying a plurality of surgical fasteners in a substantially longitudinal array to body tissue clamped between fastener holding and anvil parts of the apparatus.
Several types of surgical fastener applying devices have been developed for applying a plurality of surgical fasteners in a substantially longitudinal array to body tissue clamped between fastener holding and anvil parts of the apparatus. For example, Hirsch et al. U.S. Pat. No. 3,275,211 shows apparatus for applying two parallel rows of metal surgical staples to body tissue clamped between a staple holding cartridge and the anvil which clinches the staples when they are driven from the cartridge and part way through the tissue. Green U.S. Pat. No. 4,506,671 shows a similar type of instrument in which two-part resinous fasteners are used in place of metal surgical staples. Each two-part fastener includes a fastener part and a retainer part. The fastener parts are driven part way through the tissue so that the ends of the fastener part prongs interlock with the retainer parts which are releasably retained in the anvil part of the apparatus.
As used herein, the term "fastener" is generic to metal staples, two-part resinous fasteners, and the like. Similarly, the term "fastener holding part" is generic to the structure which initially contains metal staples or the fastener parts of two-part resinous fasteners. The term "anvil" is generic to the structure which clinches metal staples or which releasably supports the retainer parts of two-part resinous fasteners.
A number of the known instruments of the type described above have structures for generally confining the tissue to be fastened between the fastener holding and anvil parts of the apparatus. For example, the apparatus shown in the above-mentioned Green patent has a cartridge in which the fastener holding and anvil parts are pivotally connected together adjacent one end of the longitudinal fastener array. Adjacent the other end of the fastener array, a pin extends from the fastener holding part into the anvil when the cartridge is closed. Accordingly, the tissue to be fastened is generally confined between the fastener holding and anvil parts of the apparatus by the pivotal connection adjacent one end of the fastener array and by the pin adjacent the other end of the fastener array.
The above-described tissue confining structures may allow small amounts of tissue to extend beyond the ends of the staple array. In the above-mentioned Green device, for example, a small amount of tissue may remain unfastened between (1) the pivotal connection between the fastener holding and anvil parts of the cartridge, and (2) the adjacent end of the fastener array. Similarly, a small amount of tissue may remain unfastened between the other end of the fastener array and the pin which extends from the fastener holding part into the anvil. In many situations this is not a problem. In some situations, however, it may be desirable to ensure that the fastener array completely traverses the entire tissue structure. For example, this may be important in applying fasteners transversely across a large blood vessel in order to close off the vessel. If even a small portion of the transverse axis of the vessel is left unfastened, there may be unacceptable blood flow past the fastener array.
In view of the foregoing, it is an object of this invention to improve surgical fastener applying apparatus of the type described above by ensuring that the fastener array applied by such apparatus extends completely across the tissue clamped in the apparatus.
It is another object of this invention to ensure that no part of the tissue clamped in surgical fastener applying apparatus of the type described above can remain unfastened.